Jon Lester pitched for World Series winning teams in 2007 and 2013 in Boston. / Bob DeChiara, USA TODAY Sports

by Bob Nightengale, USA TODAY Sports

by Bob Nightengale, USA TODAY Sports

Jon Lester and Jonny Gomes have been traded to the Oakland Athletics in exchange for outfielder Yoenis Cespedes and a competitive balance pick in 2015, according to two baseball officials with direct knowledge of the trade.

The officials spoke to USA TODAY Sports on condition of anonymity because the trade has not yet been announced.

The A's will also receive $650,000 from the Red Sox to offset some of the remaining $13 million due Lester, who is eligible for free agency after the season.

Lester, the left-hander who keyed World Series titles in 2007 and 2013, will head to the team with baseball's best record as the Athletics continue a stunning re-tooling of an already solid club.

Lester's acquisition comes less than a month after the A's acquired Chicago Cubs ace Jeff Samardzija and Jason Hammel for two of their top prospects.

Hammel, however, has been ineffective with the A's, going 0-4 with a 9.53 ERA.

In acquiring Lester, the A's present a dominant starting quartet that by far gives them the best chance to overcome a frustrating history of first-round playoff exits. Each of the past two seasons, the A's have been eliminated in decisive Game 5s of the American League Division Series by the Detroit Tigers.

This year - assuming they maintain control of the AL West - the A's will trot out Sonny Gray, Scott Kazmir, Samardzija and Lester at a potential playoff foe.

However, they lose Cespedes, a key cog in their drive to consecutive division titles. When healthy, the two-time Home Run Derby champion has been an offensive and defensive force for the A"s, producing a .470 slugging percentage; he was on his way to a third consecutive season of at least 23 home runs. Now, many of his at-bats, at least against leftys, will be assumed by Gomes, who played on the A's 2012 division champions and the Red Sox's 2013 World Series winners.

As for Boston? It's clear the club is re-tooling, not rebuilding, in acquiring Cespedes. As part of the contract terms when he signed with Oakland after defecting from Cuba, Cespedes can become a free agent after 2015.

His right-handed bat figures to profile very well in Boston, and the club would clearly have the payroll room and resources to try and strike an agreement to sign him to a long-term deal there before he reaches free agency.

Lester, meanwhile, closes out his Boston career with a 110-63 record and a 3.64 ERA, and he won six postseason games for them -- including two World Series wins against the St. Louis Cardinals last year.